AT&T’s mobile subscribers in some U.S. states were not able to make 911 emergency calls late Wednesday, leading to complaints from police departments and emergency agencies in various parts of the country.

The FCC has previously fined service providers for outages. In July 2015, for example, the agency reached a US$17.5 million settlement with T-Mobile USA, resolving an investigation into two separate but related 911 service outages that occurred on the company’s national network in 2014 and together lasted nearly three hours, preventing T-Mobile customers from reaching first responders when making wireless 911 calls.

The outage on Wednesday will likely give momentum to plans to upgrade the current 911 system to a Next Generation 911 system that would allow people reporting emergencies to send text, images and video when reporting an emergency.

The National Emergency Number Association said Wednesday that the outage highlights the immediate need to transition 911 centers in the U.S. to the next-generation NG9-1-1 technology that can “intelligently route around outages, redirect calls to other regions, or use backup facilities in ways that legacy E9-1-1 systems cannot.”

Senators Bill Nelson, a Democrat from Florida, and Amy Klobuchar, a Democrat from Minnesota have released draft legislation to quicken the national transition to next generation 911 systems that will take advantage of new broadband and voice technologies.